1. Field of the Invention
The present invention relates to an apparatus for making a single crystal and, more particularly, is directed to an apparatus which includes a sealed vessel, a crucible received in the sealed vessel to hold a molten liquid and a floating member having an opening defining the cross sectional outline of a single crystal while being grown and floating on the molten liquid.
2. Description of the Prior Art
Japanese Patent Application Disclosure No. 54-39570 (laid open to the public inspection on Mar. 27, 1979 and corresponding U.S. patent application Ser. No. 930,696, now U.S. Pat. No. 4,196,171) discloses an apparatus for making a single crystal of III-V compound semiconductive material which includes a sealed vessel, a crucible received in the sealed vessel to hold a molten liquid of a III-V compound semiconductive material from which a single crystal is to be grown and a floating member floating on the molten liquid, the floating member having an opening defining the cross sectional outline of the single crystal during its growth and being formed of a sintered body consisting essentially of 0.5 and 10% by weight of at least one metal oxide member selected from the group consisting of an oxide of yttrium and lanthanum series elements, 0.5 to 10 by weight of aluminum oxide and the balance of silicon nitride.
Japanese Patent Application Disclosure No. 54-18816 (laid open to the public inspection on Feb. 13, 1979 and corresponding U.S. patent application Ser. No. 924,358, now U.S. Pat. No. 4,230,494) discloses material for the above mentioned floating member, which consists of a compound made of silicon nitride and metal oxide member selected from yttrium oxide, cerium oxide and aluminum oxide and silicon nitride.
However, it is not easy to produce the floating member made of the above mentioned materials because of the relatively long length of time necessary for sintering and adhering to the mold to occur.